Agree with Goggles Pizano on dip in quality...especially standard flooded lead acid batteries. A couple of years back, a string of Diehard Gold and Duralast Gold batteries were only lasting 2 years at best with regular, intermittent charging (every 4 weeks) but no tender.
The keys to any Viper's battery longevity are multiple:
First off, require full testing of new battery at the point of purchase...and, do not call ahead and give them the opportunity to charge it in advance as this will likely yield inflated readings.
Next, purists recommend fully charging the battery with an matched charger before installation. While most of us have slapped the new batteries into cars and driven off, this is not the recommended way...regardless of what Granny, Uncle Joe, and the "racer down the street" says.
Heat kills batteries. So a Viper stored in a 40-60°F environment will generally outlive the same type battery used in a 70-90°F situation.
I love tenders !! And, while I have several types of chargers, I rely on tenders...especially for the standand batteries that I formerly used in our Vipers.
Since I got tired of pulling the left rear wheel off of Gen I and II Vipers to change batteries frequently (yes, they were under warranty), I switched all of our Vipers to AGM batteries either supplied by Odyssey or Interstate ( the Interstate MTZ series has a 4 year full warranty). Three of the Vipers have had the same AGM battery in place for many years...specifically 14, 15, and 16 years. Yes, they weigh a bit more, and cost a bit more, but the longterm value is there in my eyes.
Lithium battery are a whole different category that can be better addressed by others.
Bottom line..."to each their own".